Engine ignition test device

ABSTRACT

Engine ignition test device includes serially-connected adjustable spark gap and lamp for connection in parallel to a portion of an engine ignition circuit. The adjustable spark gap comprises a fixed electrode and a pivoted movable electrode that swings away from the fixed electrode for gap adjustment. The movable electrode can be repositioned to compensate for wear. Test probes include a test connector for serial connection in high voltage ignition lines and a test sensor for detecting the external electric field on the high voltage ignition leads.

United States Patent 1 1 1 3,806,796

Goldstein Apr. 23, 1974 [5 ENGINE IGNITION TEST DEVICE 1,914,809 6/l933 Konsted 324/17 76 I tzRbeGldt' 12548M h l nven or z z g g; a Primary ExaminerMichael J. Lynch Attorney, Agent, or Firm-Allan M. Shapiro [22] Filed: Apr. 10, 1972 211 App]. No.2 242,572 ABSTRACT Engine ignition test device includes serially-connected [52] Cl. 324/17 324/122 adjustable spark gap and lamp for connection in para]- [51] Inti Chm" 6 13/42 lel to a portion of an engine ignition circuit. The ad- [58] Field of ga; 324/1549 justable spark gap comprises a fixed electrode and a 324/122 pivoted movable electrode that swings away from the fixed electrode for gap adjustment. The movable elec- [56] References Cited trode can be repositioned to compensate for wear.

Test probes include a test connector for serial connec- UNITED STATES PATENTS tion in high voltage ignition lines and a test sensor for I i f I I etecting the external electric field on the high voltage CV1 3,588,679 6/1971 Lewin 324/17 'gmuon leads 1,950,052 3/1934 Haskins 324/16 8 Claims, 8 Drawing Figures PATEMTEBAPR 23 1914 3 806' 796 sum 1 BF 2 BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is directed to an engine ignition test device, particularly for testing the high voltage components thereof. I

2. Description of the Prior Art As spark ignition engines become more highly refined, and especially as it becomes desirable to reduce undesirable gaseous discharges from such engines, much new equipment has been developed for the diagnostic analysis of spark ignition engines. Perhaps the most highly refined and most universal piece of equipment for testing the electrical ignition components and system of a spark ignition engine is the oscilloscope,

' when properly equipped with suitable auxiliaries. Oscilloscopes specially fitted out for spark ignition diagnostics are presently known in the art. When equipped in this way, they can be connected to both the low and high voltage portions of the spark ignition system for analysis of point gap dwell and point resistance on the low voltage side, as well as coil voltage and spark condition in each of the spark plugs. These devices are complex and expensive. Certain high voltage diagnostics can be accomplished without resort to such expensive equipment.

High voltage spark gaps in parallel to the spark plugs in an internal combustion engine have been known. For example, Kovac U.S. Pat. No. 2,564,764 teaches the permanent installation of a fixed high voltage spark gap in parallel to the main high voltage coil lead to indicate to the driver existence of excessive voltage conditions, upon such a malfunction. Strauss U.S. Pat. No.

' 2,496,823 teaches an adjustable spark gap for use in ignition system testing on the high voltage side of the ignition coil. However, neither of these devices provides the information nor is sufficiently flexible or convenient to use as the engine ignition test device of this invention.

SUMMARY OF THE INVENTION In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to an engine ignition test device which comprises a circuit including an adjustable high voltage spark gap serially connected to a lamp, the circuit being connectable in parallel to a portion of the high voltage section of a spark ignition engine ignition system.

It is an object of this invention to provide an engine ignition test device which is of economic construction and which is convenient and reliable to use in the test- 1 ing of the high voltage portion of a spark ignition enan engine ignition test device which is convenient to use in a plurality of different tests in various portions of the high voltage system of an engine ignition. It is a further object to provide a test device which is easy to use in a plurality of difi'erent tests in determining the voltage condition by means of the adjustable gap which is adjusted to permit an arc to ground.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with furtherobjects and advantages thereof, may be understood best by reference to'the following description, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF'THE DRAWINGS FIG. 1 is an isometric view of the engine test device of this invention, with part of the electric leads thereof broken away to indicate longer length thereof.

FIG. 2 is a rear elevational view of the main housing thereof, with a portion of the back cover broken away to show internal construction.

FIG. 3 is a section taken generally along the line 3-3 of FIG. 2.

FIG. 4 is a section taken generally along the line 4-4 of FIG. 2.

FIG. 5 is a side view, with parts broken away and parts taken in section, of the test connector structure which forms a portion of the engine ignition test device of this invention.

FIG. 6 is a side elevational view of an ignition coil, with the test connector applied thereto.

FIG. 7 is a side elevational view of a portion of a conventional distributor, showing the employment of the test connector of the test device of this invention, and this figure further showing the conventional spark plug and spark plug lead, with parts thereof broken away.

FIG. 8 is a structural schematic view of an ignition circuit for a spark ignition engine, with the circuit of the test device of this invention connected thereto.

DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the engine ignition test device of this invention is generally indicated at 10 in FIG. 1. This comprises the test unit 12 which is connected by lead 14 to test connector 16. Test sensor 18 is used with test connector 16 for certain of the tests which the engine ignition test device 10 is employed to perform.

The engine ignition test device operates on the principle of connecting a neon indicator light in series with an adjustable spark gap and connecting this series combination in parallel with various elements of the high voltage portion of the spark ignition circuit equipment of the internal combustion engine to be tested. The test unit 12 contains the neon light and the adjustable spark gap. Test unit 12 comprises a housing 20 which has the front wall 22 from which side walls 24 and 26 and end walls 28 and 30 depend to enclose interior space 32. The interior space 32 is divided by interior wall 34 which extends at least partway across the space 32. Back 36 covers the interior space 32 and may be removably secured if access to the equipment contained therein is required. Since the test device 10 is to be polymer composition materials. Back 36 is preferably similarly formed of high dielectric strength material.

Electrode post 38 (seen in FIGS. 2 and 4) is mounted through interior wall 34 and is secured thereby with a shoulder on one side of wall 34 (FIG. 2) and nut 40 on the other side of the wall. Thus, electrode post 38 is fixed in position. Electrode post 38 has a larger diameter portion 42 which has the shoulder which engages against interior wall 34, and has a smaller diameter portion 44 extending therefrom into space 32. These two portions are separated by stop shoulder 46. Both portions are conveniently cylindrical for ease of manufacture, and stop shoulder 46 is conveniently planar, and positioned normal to the axis of electrode 38. On the other hand, the smaller diameter portion 44 may not be of uniform diameter, but may be contoured for control of the spark gap, as is subsequently described; in any event, electrode portion 44 is preferably a surface of revolution about the central longitudinal axis of electrode 38 for purposes of ease of manufacture. Electrode 38 serves as one of the electrodes of the adjustable spark gap within test unit 12.

The other electrode of the adjustable spark gap is formed by rod 48. As seen in FIGS. 2, 3, and 4, rod 48 passes through an opening near the end of adjustment post 50. Adjustment post 50 passes through and is rotatable relative to the front wall 22 of test unit 12 and carries adjustment knob 52 on the front thereof. Adjustment knob 52 is secured to adjustment post 50 for rotation thereof so that the angular position of knob 52 corresponds to the angular position of post 50. Adjustment knob 52 carries reference mark 54 which cooperates with indicia 56 secured to the front wall 22 to indicate the relative rotary position of adjustment post 50 and relative angular position of rod electrode 48.

Compression spring 58 is engaged around adjustment post 50 and carries washers 60 and 62 on the inner and outer ends thereof. Washer 62 engages against rod electrode 48 to releasably restrain rod electrode 48 in its longitudinal direction. When adjustment of rod electrode 48 is desired, it is moved against shoulder 46, washer 62 is depressed against spring 58, and rod electrode 48 is pressed to the left (as seen in FIGS. 2 and 4) so that its firmly engages smaller diameter portion 44, and thereupon washer 62 is released to retain rod electrode 48 in its proper longitudinal position. In this position, adjustment knob 52 is secured to its post 50 in an appropriate angular position so that reference mark 54 indicates zero spark gap, and therefore zero voltage, on indicia 56. From this construction, it is seen that, as the knob is moved, the outer end of rod elec trode 48 swings away from shoulder 46 and increases the gap between the outer end of rod electrode 48 and the smaller diameter portion 44. Thus, the adjustable spark gap is increased. From this geometry it is seen that the adjustable spark gap increases as the sine of the angle, because the outer end of the rod electrode 48 describes a circular path in cooperation with the cylindrical smaller diameter 44. If a function other than the sine function is desired, the smaller diameter portion 44 can be appropriately shaped to produce the desired result. For practical purposes, the sine function is a desirable relationship, and indicia 56 indicate voltage values related to the spark gap.

Neon lamp 64 extends through an opening the' front wall opening 22 of test unit l2,so that it is visible from the front of the unit. It is protected by shield 66,

which protects it from mechanical damage and provides a shade to aid in its observation in brightly lighted environments. Socket 68 carries lamp 64 and is secured to the side of interior wall 34. Neon lamp 64 is preferably the type where both electrodes are visible so that polarity can be observed.

Going to the wiring interconnection of the test unit 12, ground wire 70 has a connector, such as alligator clip 72, for connection to an electrical ground in the high voltage portion of the spark ignition circuit. Ground wire 70 enters test unit 12 through end wall 28. Interiorly of end wall 28 it is connected under nut 74, which secures socket 68, and which serves as one of the socket terminals. From the other terminal side of socket 68, electrically on the other side of neon lamp 64, wire 76 connected neon lamp 64 to post 50. The end of wire 76 carries a flat ring-type wire terminal which is positioned beneath washer 60 to maintain good electrical contact. Washers 60 and 62, spring 58, and post 50 are all metallic to provide electrical connection through to metallic rod electrode 48. Test lead 14 is connected under nut 40 by a similar wire terminal and extends out of test unit 12 through end wall 28.

Test lead 14 interconnects the test unit 12 with test connector 16. As is seen in FIGS. 1 and 5, the outer end of test lead 14 is directly connected, as by swagging or soldering, to the metallic body 80 of the test connector. Socket 82 is formed in the upper end of the body for connection of standard male connector high voltage ignition lines thereto. The lower end of body 80 has a nose 84 thereon and metallic leaf spring 86 is secured to the nose. These parts are dimensioned so that they can enter into the standard female socket in high voltage ignition equipment. Resilient sleeves 88 of high dielectric strength material are positioned around the major portion of body 80 to permit its handling and to prevent stray arcs.

Test sensor 18 comprises a U-shaped metallic sensor 92 which has an open sided longitudinal channel 94 extending the length thereof. The channel 94 is of sufficient width to be able to embrace the external insulation of a high volt ignition line. It has socket attached thereto in which the male connector on test connector 16, comprised of springs 86 on nose 84, can be inserted. Test sensor 18 is of metallic material so that, when it is connected in that way, the sensor is electrically connected to test unit 12.

FIG. 8 schematically indicates the arrangement of the conventional ignition circuit in a spark ignition internal combustion engine. It shows an ignition coil 96 having a battery 98 and breaker points 100 serially connected to the low voltage turns in the coil. Conveniently, one side of that system is grounded. When points 100 are closed, current builds up in the low voltage circuit. When they are opened, the magnetic field collapse causes a high voltage impulse in the high voltage coil of ignition coil 96. This high voltage pulse appears between ground, to which one side of the high voltage coil is connected, and a female terminal in tower 102 of coil 96. Coil wire 104 conventionally connects the coil tower 102 to tower 106 on distributor cap 108. The distributor cap' 108 internally contains a rotor which passes adjacent a plurality of contacts, each of which is connected to a different spark plug 110 through plug wire 112. The spark plug 110 has a spark gap, the other side of which is connected to ground, to complete the high voltage circuit. While one spark plug is illustrated in each of P108.

understood that there are a plurality of such spark high resistance plugs and a plurality of such spark plug wires, in accorremoved from the top dance with the plurality of connections on the top of is plugged directly into the fema e te the distributor cap 1 in the usual automotive and 5 102. With the connections made in this way, the conspark ignition internal combustion engines, there are nectrons are in the usual, non-test arrangement. Nose four to eight spark plugs, one for each cylinder, and the 84 with its leaf spring connectors 86 are plugged into and sockets for connection receptacle 90 in test sensor 18. The gap 114 is set to of the plug wires into the distributor cap zero so that the electrodes 38 and 48 are in contact F105. 6 and 8 illustrate the method of connection of 10 with each other. With the engine running, test sensor the engine ignition test device 10 into an ignition crr- 18 is successively placed around each one 0 he spar cuit for the initial and principal tests. in this position, plug wires For hose wires 112 which have t e 64 will glow only the test connector 16 is plugged into the female terminormal resistance value, the lamp nal in the top of tower 102 on ignition coil 96, while the very faintly, or not at all. if the dial is turn coil wire 104 is plugged therein. Knob 54 is adjusted so kilovolts, the glow will disappear. if the wire 15 defecthat the spark gap between electrodes 38 and tive due to high resistance, the light w'll glow more fairly large. it is preferred that the indicia 56 indicate brightly. if the dial is turned to 1 or 2 kilovolts, the light flash brightly at both electrodes. Modern cars use carbetween the electrodes, to thus indicate the state of th bon core resistance spark plug wires. The carbon someby mechanical damage or e ment in parallel to it. On the first test, it is as- 20 times fails inside the wire sumed that the spark plugs 110 have been determined burning, thus causing a break in the continuity of the wire, and therefore causing high resistance.

100 similarly determined to be in good condition an The engine ignition test device 10 can also be emadjustment. Preferably both the spark plugs and points ployed to determine the condition of ignition COli 96 have been replaced and set. in this test, test connector 16 is installed in the terminal The adjustable spark gap 114 between electrodes 38 on top of coil 96, as shown in FIG. 6, and the coil wire and 48 is adjusted so that it will not arc across until 104 18 connected, also as shown in H6. 6. One spark about kv (kilovolts) are applied thereto. While parplug wire is removed and the gap 114 is adjusted so that about 30 kv to are across, and the engine is ticular values of voltage are given in this specification it requires nsion, it is under- 30 started. lf the lamp 64 flashes, it indicates good condito represent corresponding gap dime stood that they are examples of what is expected in tion of coil 96. If the lamp 64 does not flash, dial 52 rs resent-day automotive equipment. Different values with change in design and with different applications produce sufficient voltage to a may suggest d'fferent numerical values than those set time the gap forth herein. to about 20 kv, the coil 96 is below specification. The Thereupon, the en ine is started and will run norvalue of 25 kv is moderately good, and 20 kv is fair, but

mally and properly if all the equipment is in good conat this value t dition. Knob 54 is turned slowly to reduce the gap between electrodes 38 and 48 and, if the gap between the terminal on the top of cor 9 the rotor and the fixed terminals in distributor cap 108 40 and the coil wire 104 is inserted in the top of the test are correct, and if all connection wires are in good conconnector. ith the gap 114 adjusted to about 25 kv, dition, the light 64 will not flash until the gap 114 is the engine is started. The gap is slowly reduced. If the rrnal light flashes on and the engine stalls above about 10 kv closed to about l0 kv or slightly less. This is the no of there is excessive resistance common to all spark plug arc voltage of the series connection the rotor gap and spark plug gap when they are both in toleranc connections. There are two things common to all of th' When the battery 98 and spark coil 96 are correctly inspark plug circuits. The first is coil wire 104, and th stalled,the illumination of one side of the light64starts second is the gap between the rotor and the fine flashing due to a reduced gap 114, the engine stalls incontacts within distributor cap 108. ln determining tl dicating that the parallel circuit through gap 114 is arccondition of wire 104, the test connector 16 is removt is the from the top of coil 96 and is placed in the center te usual condition indicating good condition of the equipminal of distributor 108, as shown in 1G. 7. Coil W1 ment, when the lamp 64 starts flashing and the engine 104 is connected to the stalls at about 10 kv. When the coil and battery are nector 16. This takes wire 104 out of the test. The correctly installed, provided the engines have the same upon, the gap 114 is adjusted to about 30 kv, and ground polarity (negative in most American cars) e engine is star ed. Knob 52 is slowly adjusted to red ap is then reduced the same electrode and the light gap 114, and if lamp 64 does not flash and the eng itrarily called the n gdoes not stall until about 10 kv is reached, it is shr ative ground electrode. 1f the coil or battery is ins that the coil wire 104 is defective in having exces with wrong polarity the other or positive electrode will resistance. However, should that wire prove to b flash on. tolerance, test of the rotor gap is ma e. This is mad lf the lam 64 starts flashing at a higher are voltage placing test connector 16 in the female socket w P value than 10 kilovolts, as the gap 114 is reduced spark plugwire 112 18 normally plugged into distril toward l0 kilovolts but the engine does not stall until cap 108, and the wire 112 is plugged into the top about 10 kilovolts is reached, this indicates that one or 65 test connector 16. This removes the rotor gap froi more of the plug wires 112 is defective, because the test. Coil wire 104 is connected into its usual so higher voltage is applied across gap 114 at some distrib- With the gap 114 adjusted to 30 kv, the eng utor rotor positions. started. Thereupon, knob 54 is 3,806,796 7 114. If the light 64 flashes on abo 10 k e problem that, as said 4m vable electrode swings about said is excessive rotor gap within the distributor cap. Re a ustmen axis, e a between said fixed elecplacement of either or both t e rotor and cap will solve r e and said movable e is gap problem. n some circumsta lectrode is between said smaller portion and said movable electrode. n may be shorted to gro n The engine ignition test device of claim 2 wherein: u d. To determine this condition, the test connector 16 p e said smaller portion is cylindrical about said fixed orc 0 ,ass own inFI axis. ut it may be p aced in the high voltage coil connec 4. An engine ignition test device comprising: tion, as shown in FIG The g 11 is set or a value etween e are voltage va aving an adjustable spark is, an adjustment post stment axis, said adjustment from the exterior of said test unit id m extending through an opening in said adjustment us, grounding of post; and

en the distributor cap and the spark plug is indicated.

y these tests, the engine i ing in said adjustment gnition test device is employed to test a number f d' so t at said movable electrode is movable against said fixed electrode by 0 ifierent characteristics of motion throu pening in said ad ustment post the high voltage portion of the ignition system in the o compensate for are wear on said movable elec spark ignition internal com ustion engi trod ile particular e diments of the present inven- 5. The engine ignition test device of claim 4 wherein tion have en sho n and described, will e obvious 0 those skilled the art that changes and modificasaid ad ustment t carries a knob on the front of ions ma made without departing from this invensaid test unit on in its bro der aspects a d, there ore, the aim in the said spring engages said ad ustable electrode interi upended clai s is cover ll uch c anges and modi- 5 orly of sa d st un .ations as fall within th rue spirit d scope of th e engine ignition test device of claim 4 wherein n What is claimed is: said fixed electrode has a stop shoulder thereon and An engine ignition test device mp g a test t having a sari lly connected ad table park a said movable electrode is rotatable about said adjust I a lamp, and a test connector serially connected to ment axis from on wh is in engagement ad ustable spark gap, sa d la p in visible exte with said stop shoulder to a ition whe e it is out y of said test u it, t e improvement wherein said 0 engagement wi stable spar ap comprises:

said stop shoulder 7. e engine ignition test devic ving a stop shoulder thereon; and I ixed axis and said fixed electrode has a smaller portion, extending novable electrode manually adjustably rotatable along said fixed axis aw om the exterior of said test unit about an adjustay from said shoulder so -that, as said movable electrode swings about said lent axis non-coaxial with said fixed axis from a adjustment axis, the gap between said fixed elec- )sition where it is in engagement with said stop trode and said mo oulder to a position wh ere it is out of engagement th said stop shoulder. ie engine ignition test device ofclai vable electrode is etween said smaller portion and i movable electrode. e engine ignition test device of claim 7 wherein: m 1 wherein:

ixed electrode has a small said smaller portion is cylindrical eiportion extending ig said fixed axis away fr about said fixed axis. om said shoulder so 

1. An engine ignition test device comprising a test unit having a serially connected adjustable spark gap and a lamp, and a test connector serially connected to said adjustable spark gap, said lamp being visible exteriorly of said test unit, the improvement wherein said adjustable spark gap comprises: a fixed electrode having a stop shoulder thereon; and a fixed axis and a movable electrode manually adjustably rotatable from the exterior of said test unit about an adjustment axis non-coaxial with said fixed axis from a position where it is in engagement with said stop shoulder to a position where it is out of engagement with said stop shoulder.
 2. The engine ignition test device of claim 1 wherein: said fixed electrode has a smaller portion extending along said fixed axis away from said shoulder so that, as said movable electrode swings about said adjustment axis, the gap between said fixed electrode and said movable electrode is between said smaller portion and said movable electrode.
 3. The engine ignition test device of claim 2 wherein: said smaller portion is cylindrical about said fixed axis.
 4. An engine ignition test device comprising: a test unit, said test unit having an adjustable spark gap and having a lamp visible from exteriorly of said test unit serially connected to said spark gap and a test connector serially connected to said adjustable spark gap, said adjustable spark gap comprising: a fixed electrode having a fixed axis; a movable electrode rotatable on an adjustment axis non-coaxial with said fixed axis, an adjustment post positioned on said adjustment axis, said adjustment post being manually adjustable from the exterior of said test unit, said movable electrode being a rod extending through an opening in said adjustment post; and a spring engaging said movable electrode in its opening in said adjustment post, so that said movable electrode is movable against said fixed electrode by motion through its opening in said adjustment post to compensate for arc wear on said movable electrode.
 5. The engine ignition test device of claim 4 wherein: said adjustment post carries a knob on the front of said test unit; and said spring engages said adjustable electrode interiorly of said test unit.
 6. The engine ignition test device of claim 4 wherein: said fixed electrode has a stop shoulder thereon; and said movable electrode is rotatable about said adjustment axis from a position where it is in engagement with said stop shoulder to a position where it is out of engagement with said stop shoulder.
 7. The engine ignition test device of claim 6 wherein: said fixed electrode has a smaller portion extending along said fixed axis away from said shoulder so that, as said movable electrode swings about said adjustment axis, the gap between said fixed electrode and said movable electrode is between said smaller portion and said movable electrode.
 8. The engine ignition test device of claim 7 wherein: said smaller portion is cylindrical about said fixed axis. 